//
//  String + toDuration.swift
//
//  Copyright (c) 2017 Ben Murphy
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in all
//  copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
//  SOFTWARE.
//

import Foundation

extension String {

    /// Convert the string representation of a time duration to a Time Interval.
    ///
    /// - Returns: A TimeInterval.
    func toDuration() -> TimeInterval? {
        let comps = self
            .trimmingCharacters(in: .whitespacesAndNewlines)
            .components(separatedBy: ":")

        guard
            !comps.contains(where: { Int($0) == nil }),
            !comps.contains(where: { Int($0)! < 0 })
            else { return nil }

        return comps
            .reversed()
            .enumerated()
            .map { i, e in
                (Double(e) ?? 0)
                    *
                    pow(Double(60), Double(i))
            }
            .reduce(0, +)
        
    }
    
}


